This invention relates to a new and improved test method and apparatus for testing ignition modules and components of gas burners.
Ignitor circuits for gas burners have been replacing conventional pilot ignition devices, and typical patents covering these devices are described in U.S. Pat. Nos. 4,626,192; 3,902,839; 4,070,143; and, 4,077,762. Other patents in the general area of ignitor testing include U.S. Pat. Nos. 2,899,675; 3,320,440; 3,597,139; 3,906,341; 3,906,342; and, 3,908,117.
The ignitor control circuits produce sequencing steps for firing a gas burner, the first step of the sequence commencing when a thermostat for the system inputs a demand signal for heat. In the second step of the sequence, and simultaneously with the demand signal, sparking begins, and a pilot gas valve opens to admit fuel gas. In the third step of the sequence, the spark ignites the pilot gas, and the ensuing flame is sensed by a sensor. In the fourth step of the sequence, the sensor opens the main gas valve, and finally, in the fifth step of the sequence, the pilot flame ignites the main gas feed supply.
The ignitor circuits which may be tested by the method and apparatus of this invention include those manufactured by Robertshaw (models SP 715 and SP735), Johnson Controls G60 series, and Honeywell S86 (Y86).
Frequently, if the ignitor circuit does not turn on the gas burner, the entire system of course must be checked to determine the problem, and this involves checking each individual component, including the ignition control module. However, this procedure, while necessary, takes time, say about 1/2-1 hours, and it would be preferable to complete the test procedure in say 10-15 minutes.
Also, it would be highly desirable to test the system without requiring the presence of a gas feed as part of the test program. Moreover, since one of the main problems associated with failure to turn on the gas burner resides in the ignition control device, a method and apparatus is desired to quickly test this components, since it represents a major potential for failure. By confirming or eliminating at the outset whether the ignition control is or is not at fault, the test program can be greatly accelerated. This would in turn determine whether to replace this component immediately before continuing the test, since it is the most expensive and complex component in the system.